A GMT watch (Greenwich Mean Time watch) can track two time zones at the same time using a 24-hour format. These watches are great for pilots, anyone who travels, works across different time zones, or wants to keep track of family or business overseas. GMT watches can also be big collector items.
Here’s a deeper look at what “GMT” means, how these timepieces work, and why they’re so popular. If you’re interested, we have a full guide explaining watch complications.
Quick Look | GMT Watch Meaning
- A GMT watch tracks two time zones at once
- It uses an extra hand that runs on a 24-hour scale
- The main hands show local time
- The GMT hand shows a second time zone
- Some GMT watches can track a third time zone using a bezel
- Popular with travelers, professionals, and collectors
What Does GMT Mean on a Watch?
GMT stands for Greenwich Mean Time. It’s the reference time set at the Prime Meridian in Greenwich, England. Before the world agreed on a shared time standard, cities used local solar time, which made travel and communication confusing.
Early GMT watches were set to Greenwich time by default, but modern GMT watches let you track any second time zone you choose. The extra hand and 24-hour scale make it easy to see another location’s time at a glance, day or night.
Popular time zone examples:
- London: GMT +0
- New York: GMT -5
- Tokyo: GMT +9
Many modern GMT watches are designed with travel in mind. Brands like Tudor have become especially popular for producing durable, legible GMT models that balance function with everyday wearability.
How Does a GMT Watch Work?
A GMT watch adds a fourth hand that moves on a 24-hour scale. Your regular hands show local time, while the GMT hand tracks a second time zone. On many modern GMT watches, you can adjust the local hour hand without stopping the watch, making travel easier. If the watch has a rotating bezel, you can even track a third time zone by turning it.
A standard GMT watch includes:
- A fourth hand that completes one full rotation every 24 hours
- A 24-hour scale on the dial or bezel
- Regular hour and minute hands for local time
- (On many models) independently adjustable hour hand for easy travel use
What’s the Difference Between a GMT Watch and a Dual Time Watch?
GMT watches use a 24-hour hand to track a second time zone. A dual time watch usually shows the second time on a 12-hour dial or sub-dial. If there’s no AM/PM indicator, you may have to guess whether it’s morning or night in that second location. The image below also features a dual time watch called the A. Lange & Sohne Lange 1 Time Zone 136.029.
How to Use the Bezel on a GMT Watch
On some watches, the GMT hand is linked to the main hour hand. When you adjust the local time, both hands move together. To track a second time zone, rotate the bezel until the correct hour aligns with the GMT hand.
Most modern watches have an independent hour hand and a separate GMT hand. This setup allows you to adjust local time without moving the GMT hand, making travel much easier. If your watch also has a rotating 24-hour bezel, you can track a third time zone by rotating the bezel forward or backward as needed. You may also not see an hour-scale bezel. The Omega Seamaster Aqua Terra GMT displays the 24-hour scale directly on the dial.
If you’re curious how timing bezels actually work in real-world use, this short video shows how a rotating bezel was originally used by divers to track elapsed time at a glance—no electronics required.
How to Read and Set a GMT Watch
Using a GMT watch is easier than it looks. Once you understand what each hand does, it becomes very intuitive.
How to Read a GMT Watch:
Start with the regular hour and minute hands. These show your local time, just like any other watch. Look at the GMT hand. It points to a 24-hour scale on the bezel or dial. That number tells you the time in your second time zone.
How to Set a GMT Watch:
Set the GMT hand to your home time using the 24-hour scale. Set the regular hour hand to your local time. On watches with an independent hour hand, you can do this without moving the GMT hand. If your watch has a rotating bezel, turn it to track a third time zone by aligning the bezel numbers with the GMT hand.
Final Thoughts | Why Choose a GMT Watch?
A GMT watch is great for travel, work, or staying connected with people in different places. It also adds character to a watch without complicating it.
If you’re ready to upgrade, this can be a great time to sell your used watch or explore trade-in options toward a GMT model that fits your style and needs. Visit our Lower Gwynedd Township showroom to shop our current selection.
FAQs
1. Can I use a GMT watch as a compass?
If you can see the sun, point the GMT hand toward it. In the Northern Hemisphere, the 12 o’clock marker will point north. In the Southern Hemisphere, it will point south.
2. What are some popular GMT models?
Some of the most popular GMT timepieces are the Tudor Black Bay GMT and the Longines Hydroconquest GMT.
3. Can a GMT watch track a third time zone?
A GMT watch can track a third time zone using the rotating 24-hour bezel and the GMT hand. Set the GMT hand to one time zone, the regular hour hand to local time, and turn the bezel to read a third zone as needed.
4. What does the 24-hour hand on a GMT watch do?
The 24-hour hand shows the time in a second time zone. It moves once around the dial every 24 hours.
5. Can you use a GMT watch every day?
A GMT watch functions like a standard watch for daily wear. The extra hand stays out of the way unless you need it, making it practical even when you’re not traveling.
